U.S. patent application number 12/215273 was filed with the patent office on 2009-01-01 for device for measuring positions of structures on a substrate.
This patent application is currently assigned to Vistec Semiconductor Systems GmbH. Invention is credited to Tillmann Ehrenberg, Uwe Goetz, Guenter Schieferstein.
Application Number | 20090002720 12/215273 |
Document ID | / |
Family ID | 40160018 |
Filed Date | 2009-01-01 |
United States Patent
Application |
20090002720 |
Kind Code |
A1 |
Ehrenberg; Tillmann ; et
al. |
January 1, 2009 |
Device for measuring positions of structures on a substrate
Abstract
A device for measuring positions of structures (3) on a
substrate (2) is disclosed, wherein the device is enclosed by a
climatic chamber (30). An illumination and imaging means (6, 14) is
also arranged in the climatic chamber (30). At least one loading
station (32) for substrates is formed on an outer wall (30a) of the
climatic chamber (30), wherein at least one transport means (34,
40) for transporting the substrates is provided within the climatic
chamber (30). A means (36) for orienting the substrates (2) with
respect to a coordinate system of the coordinate measuring machine
(1) is provided, wherein the transport means (34, 40) deposits the
substrates (2) on the means (36) for orienting.
Inventors: |
Ehrenberg; Tillmann;
(Schoeffengrund, DE) ; Goetz; Uwe;
(Braunfels-Neukirchen, DE) ; Schieferstein; Guenter;
(Huettenberg, DE) |
Correspondence
Address: |
SIMPSON & SIMPSON, PLLC
5555 MAIN STREET
WILLIAMSVILLE
NY
14221-5406
US
|
Assignee: |
Vistec Semiconductor Systems
GmbH
Weilburg
DE
|
Family ID: |
40160018 |
Appl. No.: |
12/215273 |
Filed: |
June 26, 2008 |
Current U.S.
Class: |
356/615 |
Current CPC
Class: |
G01B 11/005
20130101 |
Class at
Publication: |
356/615 |
International
Class: |
G01B 11/14 20060101
G01B011/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 27, 2007 |
DE |
10 2007 030 203.9 |
Claims
1. A device for measuring positions of structures on a substrate,
comprising a climatic chamber enclosing the device, wherein the
device includes a coordinate measuring machine and a measurement
table movable in one plane, an illumination and imaging means is
arranged in the climatic chamber, at least one loading station for
substrates is formed on an outer wall of the climatic chamber, at
least one transport means for transporting the substrates is
provided within the climatic chamber, means for orienting the
substrates with respect to a coordinate system of the coordinate
measuring machine, wherein the transport means deposits the
substrates on the means for orienting.
2. The device of claim 1, wherein the means for orienting is
arranged in the climatic chamber.
3. The device of claim 2, wherein the means for orienting is
arranged in at least one air flow formed in the climatic
chamber.
4. The device of claim 1, wherein the means for orienting is
associated with the device for measuring positions of structures
outside the climatic chamber, as a separate means.
5. The device of claim 1, wherein the means for orienting of
substrates carries out a defined rotation.
6. The device of claim 1, wherein a robot deposits the substrate on
the means for orienting the substrate and is associated with the
loading station.
7. The device of claim 1, wherein an illumination means and a
camera acquiring an image of at least part of the substrate are
associated with the means for orienting.
8. The device of claim 7, wherein the camera includes an evaluation
unit for identification of the substrate.
9. The device of claim 7, wherein the camera captures a full image
of the substrate and that the orientation of the substrate may be
determined from the full image of the substrate.
10. The device of claim 9, wherein the means for orienting is
connected to at least one computer setting an orientation of the
mask input by the user.
11. The device of claim 10, wherein the computer is provided for
the image evaluation of the images acquired by the camera.
12. The device of claim 1, wherein a magazine for depositing
substrates is also associated with the coordinate measuring machine
in the climatic chamber.
13. The device of claim 1, wherein the coordinate measuring machine
in the climatic chamber includes a granite block on which the
movable measurement table is arranged.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority of German Patent
Application No. 10 2007 030 203.9, filed on Jun. 27, 2007, which
application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a device for measuring
positions on a substrate. In particular, the invention relates to a
device for measuring positions on a substrate, wherein the device
is enclosed by a climatic chamber. The device itself includes a
coordinate measuring machine comprising a measurement table movable
in one plane. An illumination and imaging means is also arranged in
the climatic chamber. At least one loading station for substrates
is formed on an outer wall of the climatic chamber. At least one
transport means for transporting the substrates is provided within
the climatic chamber.
BACKGROUND OF THE INVENTION
[0003] A coordinate measuring device for measuring structures on
wafers and masks used for their production is known from the
lecture script "Pattern Placement Metrology for Mask Making" by Dr.
Carola Blasing. This lecture was given on the occasion of the
Semicon conference, Education Program, in Geneva on Mar. 31, 1998.
The description given therein is the basis for a coordinate
measuring device as it is commercially available in many forms.
[0004] The German published application DE 19949005 discloses a
means and a method for introducing various transparent substrates
into a high-precision measuring device. The means is enclosed by a
climatic chamber. Within the climatic chamber, there is, for
example, provided a magazine having several compartments in which
substrate holders for various substrates are deposited.
Furthermore, a loading station via which substrates may be
introduced into the climatic chamber is provided on at least one
outer wall of the climatic chamber. Within the climatic chamber,
there is also provided an automatic transfer means withdrawing
substrates from the magazine and transporting them to the loading
station or positioning them on the measurement table of the
means.
SUMMARY OF THE INVENTION
[0005] It is the object of the present invention to configure a
device for measuring positions of structures on a substrate such
that the substrate may be deposited with various orientations on a
measurement table. The device is also supposed to allow the
determination of the current orientation of a mask or a
substrate.
[0006] This object is achieved by a device for measuring positions
of structures on a substrate comprising: a climatic chamber
enclosing the device, wherein the device includes a coordinate
measuring machine and a measurement table movable in one plane, an
illumination and imaging means is arranged in the climatic chamber,
at least one loading station for substrates is formed on an outer
wall of the climatic chamber, at least one transport means for
transporting the substrates is provided within the climatic
chamber, means for orienting the substrates with respect to a
coordinate system of the coordinate measuring machine, wherein the
transport means deposits the substrates on the means for orienting
the substrates.
[0007] For the present invention, it is advantageous that a means
for orienting the substrates with respect to a coordinate system of
the coordinate measuring machine is associated with the device for
measuring positions of structures on a substrate. The substrates
may be deposited on the means for orienting the substrates by a
provided transport means.
[0008] The means for orienting may be arranged within the climatic
chamber. It is advantageous if the means for orienting the
substrates is arranged in at least one air flow formed in the
climatic chamber.
[0009] According to a further advantageous embodiment of the
invention, the means for orienting may be arranged outside the
climatic chamber. The means for orienting the substrates is a
separate means that may be associated with the device for measuring
positions of structures on substrates.
[0010] The orienting of the substrates may be defined as rotating.
The orienting of the substrates may also be defined turning. It is
further contemplated that the orienting of the substrates is
defined as rotating and turning.
[0011] A robot depositing the substrate on the means for orienting
the substrate may be associated with the loading station.
[0012] The means for orienting includes an illumination means and a
camera. At least part of the substrate may be captured by the
camera. An evaluation unit for an identification of the substrate
may also be associated with the camera. It is also contemplated
that a full image of the substrate may be acquired by the camera.
The orientation of the substrate may then be determined from the
full image. For this purpose, at least one computer determining the
orientation of the substrate and/or setting an orientation of the
substrate or the mask input by the user is associated with the
means for orienting.
[0013] A magazine for depositing substrates may also be associated
with the coordinate measuring machine in the climatic chamber. The
coordinate measuring machine may further include a granite block on
which the movable measurement table is arranged.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the following, embodiments and their advantages will be
explained in more detail with reference to the accompanying
figures.
[0015] FIG. 1 schematically shows a prior art coordinate measuring
device;
[0016] FIG. 2 shows a first embodiment of the device for measuring
positions of structures on a substrate, wherein the means for
orienting the substrates is mounted in the climatic chamber;
[0017] FIG. 3 shows a further embodiment of the device, wherein the
means for orienting is mounted outside the climatic chamber and is
thus an independent unit;
[0018] FIG. 4 shows a schematic representation, wherein the means
for orienting is arranged within an air flow in the climatic
chamber;
[0019] FIG. 5 shows a schematic representation of a mask or
substrate provided with a marking based on which the orientation of
the substrate may be determined; and,
[0020] FIG. 6 shows a schematic representation of a capturing means
for determining the orientation of the substrate or the mask.
DETAILED DESCRIPTION OF THE INVENTION
[0021] FIG. 1 shows a coordinate measuring machine 1 as already
known in several forms in prior art. Coordinate measuring machine 1
includes a granite block 25 on which a measurement table 20 movable
in the X-coordinate direction and in the Y-coordinate direction is
positioned to be displaceable on corresponding air bearings 21.
Measurement table 20 carries a substrate or a mask 2 to which
several structures 3 are applied. The position of measurement table
20 is measured by means of a laser interferometer 24 directing a
laser measurement beam 23 onto measurement table 20. Granite block
25 is mounted on legs 26 with an anti-vibration arrangement. An
incident light illumination means 14 and a transmitted light
illumination means 6 are provided. Transmitted light illumination 6
directs the light beam originating therefrom to a deflecting mirror
7 which, via a condenser 8 provided with an aperture 8a,
illuminates substrate or mask 2. The light coming from transmitted
light illumination source 6 reaches substrate 2 via an illumination
light beam 4. Opposite structures 3, a measurement objective 9 is
provided which may be moved in the Z-coordinate direction by a
moving means 15 to thus set various focus positions. The light
coming from incident light illumination light source 14 reaches
substrate 2 via an aperture 9a of measurement objective 9. The
light coming from substrate 2 also passes through measurement
objective 9 and is deflected to a detector 10 by means of a beam
splitter 12. Detector 10 may be implemented as a camera having a
computer 16 associated therewith which generates a digital image
from the captured light signals. In a particular embodiment,
detector 10 may be provided with a CCD chip 11.
[0022] FIG. 2 shows a first embodiment of the device for measuring
structures on substrate 2. Coordinate measuring machine 1 is shown
only schematically and is represented by measurement table 20 and
substrate 2 deposited on measurement table 20. Coordinate measuring
machine 1 is arranged within a climatic chamber 30. An outer wall
30a of climatic chamber 30 may be provided with a loading station
32. Loading station 32 is followed by a transport means 34. With
the help of transport means 34, the substrate or the mask may be
transferred to a means 36 for orienting the mask. A further
transport robot 40 which receives the mask from the transport means
and, if necessary, deposits it on measurement table 20 is also
associated with transport means 34. It is also contemplated that,
within climatic chamber 30, a magazine 38 is provided, where
several substrates or masks 2 are put in intermediate storage
before they are subjected to measuring by means of coordinate
measuring machine 1. Robot 40 arranged within the climatic chamber
may thus be moved along a double arrow 42 to receive and deposit
the masks correspondingly.
[0023] FIG. 3 schematically shows a further embodiment of the
present invention. Means 36 for orienting mask 2 is arranged as an
independent unit outside climatic chamber 30. In a further outer
wall 30b of climatic chamber 30, an interface 44 is formed via
which the substrates oriented by means 36 for orienting the
substrates may be passed on to a further transport means 34 inside
climatic chamber 30.
[0024] FIG. 4 shows the embodiment of the present invention in
which means 36 for orienting substrates 2 is arranged in at least
one air flow 50. Air flow 50 is formed within climatic chamber 30.
In the illustration chosen, climatic chamber 30 is indicated by a
broken line. A ventilator means 48 may be connected to climatic
chamber 30, the ventilator means being suitable to generate a
corresponding air flow within climatic chamber 30. For air flow 50
directed towards means 36 for orienting the substrates to form, air
guiding plates 52 may be provided in climatic chamber 30. It is
particularly advantageous if means 36 for orienting the substrates
is formed within air flow 50, because in that way potential
contaminations or particles on mask 2 may be removed by air flow
50.
[0025] FIG. 5 shows a schematic representation of mask 2 provided
with several markings for the identification of mask 2. On the one
hand, mask 2 may be provided with a bar code 54. It is also
contemplated that the mask is provided with at least one number and
letter coding 56. Based on markings 54, 56, the orientation of the
mask may thus be determined and established by suitable image
processing.
[0026] FIG. 6 shows a schematic representation of means 36 for
orienting substrates or masks 2, which is connected to a computer
60. Means 36 for orienting mask 2 includes a rotary plate 62 with
which the desired orientation may be set via computer 60. Opposite
the mask, a camera 64 may be associated via which marking 54 or 56
of mask 2 is read and the orientation is determined therefrom by
computer 60. It is also contemplated that the whole surface of the
mask may be captured by camera 64, whereby the orientation of the
mask may then be determined from the corresponding structures or
markings. Essentially, orientations in steps of 90.degree. are set
for means 36 for orienting. The oriented masks 2 are then
transferred to coordinate measuring machine 1 for measuring the
structures. With the help of means 36 for orienting mask 2, it is
possible to perform automatic setting of the orientations of mask 2
without withdrawing the mask from the coordinate measuring machine
and re-transferring it thereto with a new orientation. The presence
of means 36 for orienting mask 2 thus allows higher throughput for
the measurement of masks 2. It is immediately clear that a
significant amount of time may be saved by this method. For the
automatic orientation of the mask, the mask is no longer withdrawn
from the climatic chamber, so that it may also be returned to the
measuring process after orienting. Repeated time-consuming
temperature adaptation of the mask is thus avoided.
* * * * *